AzureAD MSGraph Add user in Administrative Unit

HI !

I use a powershell script to create users in my Azure environnement and I want to put each one of them in a specific Administrative unit.

For technical reasons I must do this with powershell core 7 and MS graph api because it's in an app.

I have all credentials to read and write with my app in Administrative Unit

For the moment I can read the administrative units, but whan I want to add an user in one of them I have always the same error (400) invalide request.

My code :

$UriAAU = https://graph.microsoft.com/v1.0/directory/administrativeUnits/{Administrative unit Id}/members/{user id}"
$AddUserAAU = Invoke-RestMethod -Uri $UriAAU -Method POST -Headers $authorization -Verbose:$false -ContentType "application/json"

$UriAAU return a valid Uri with Administrative unit and user id.

Did someone ever try that ? did it worked ?

Thank you !!

Alex69570